Wolf: Add 2GB memory support in mosys.

Add 2GB memory support in mosys for probing HWID.
BRANCH=master
BUG=chrome-os-partner:23534
TEST=execute "mosys -v -l memory spd print id"
Check the output of the command having the deisred memory information.

Change-Id: I1863bb1c1d7d51af05c74b341cf5a15c3655e1ce
Signed-off-by: chuckche <chuck.chen@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/176780
Reviewed-by: Mohammed Habibulla <moch@google.com>